1. Field of the Invention
The present invention relates to a liquid crystal display apparatus in which each pixel is constructed by a plurality of sub-pixel structures.
2. Description of the Related Art
In recent years, as a display monitor of a liquid crystal television, a notebook-sized personal computer, a car navigation, or the like, for example, a liquid crystal display apparatus employing a VA (Vertical Alignment) mode using a vertical alignment liquid crystal is proposed. In the VA mode, a liquid crystal molecule has a nature of negative anisotropic permittivity, that is, the permittivity in the major-axis direction of the molecule is lower than that in the minor-axis direction, and a view angle wider than that in the TN (Twisted Nematic) mode is realized.
The liquid crystal display apparatus using the liquid crystal in the VA mode has, however, a problem such that luminance in the case where the display screen is seen from front and that in the case where the display screen is seen obliquely are different from each other. Concretely, the luminance characteristic in the case where the display screen is seen from front and that in the case where the display screen is seen, for example, in the direction of 45 degrees are largely different from each other (fluctuation to higher luminance). Such a phenomenon is called “wash out”, i.e. upward luminance shift, “color shift”, or the like and is the biggest drawback in a liquid crystal display apparatus in the case of using the liquid crystal in the VA mode.
As a measure for correcting the “foggy” phenomenon, a structure of dividing a unit pixel into two sub-pixels and making thresholds in the sub-pixels to be different from each other (multi-pixel structure) is proposed (for example, Japanese Unexamined Patent Application Publication No. 2007-86791.
Concretely, for example, in a multi-pixel structure (the structure of a pixel 120) illustrated in FIG. 14, two sub-pixels 120A and 120B are provided in the pixel 120. In the two sub-pixels 120A and 120B, liquid crystal elements 122A and 122B are formed, respectively. To the liquid crystal elements 122A and 122B, TFT (Thin Film Transistor) elements 121A and 121B are directly connected. To the TFT elements 121A and 121B, a common gate line G is connected, and data lines DA or DB are connected, respectively. With such a configuration, different drive voltages are applied to the sub-pixels 120A and 120B.
For example, in a multi-pixel structure (the structure of a pixel 120-1) illustrated in FIG. 15, the drive voltage is applied directly from a TFT element 121 to the sub-pixel 120A as one of the two sub-pixels 120A and 120B, and the drive voltage is applied from the TFT 121 to the other sub-pixel 120B via a connection line L101 and a capacitive element 123B. With such a configuration, different drive voltages are applied to the sub-pixels 120A and 120B.